Use ansi color in the dartanalyzer cli output.

pkg/analyzer_cli/test/reporter_test.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library analyzer_cli.test.formatter;
 
 import 'package:analyzer/analyzer.dart';
+import 'package:analyzer_cli/src/ansi.dart' as ansi;
 import 'package:analyzer_cli/src/error_formatter.dart';
 import 'package:test/test.dart' hide ErrorFormatter;
 import 'package:typed_mock/typed_mock.dart';
 
 import 'mocks.dart';
 
 main() {
   group('reporter', () {
     var out = new StringBuffer();
     var stats = new AnalysisStats();
 
-    setUp(() => stats.init());
-    tearDown(() => out.clear());
+    setUp(() {
+      ansi.runningTests = true;
+      stats.init();
+    });
+
+    tearDown(() {
+      out.clear();
+      ansi.runningTests = false;
+    });
 
     // Options
     var options = new MockCommandLineOptions();
     when(options.enableTypeChecks).thenReturn(false);
     when(options.hintsAreFatal).thenReturn(false);
     when(options.machineFormat).thenReturn(false);
     when(options.verbose).thenReturn(false);
 
     var reporter = new ErrorFormatter(out, options, stats);
 
     test('error', () {
       var error = mockError(ErrorType.SYNTACTIC_ERROR, ErrorSeverity.ERROR);
       reporter.formatErrors([error]);
 
       expect(out.toString().trim(),
-          '[error] MSG at /foo/bar/baz.dart:3:3 (mock_code).');
+          'error • MSG at /foo/bar/baz.dart:3:3 • mock_code');
     });
 
     test('hint', () {
       var error = mockError(ErrorType.HINT, ErrorSeverity.INFO);
       reporter.formatErrors([error]);
 
       expect(out.toString().trim(),
-          '[hint] MSG at /foo/bar/baz.dart:3:3 (mock_code).');
+          'hint • MSG at /foo/bar/baz.dart:3:3 • mock_code');
     });
 
     test('stats', () {
       var error = mockError(ErrorType.HINT, ErrorSeverity.INFO);
       reporter.formatErrors([error]);
       stats.print(out);
       expect(
           out.toString().trim(),
-          '[hint] MSG at /foo/bar/baz.dart:3:3 (mock_code).\n'
+          'hint • MSG at /foo/bar/baz.dart:3:3 • mock_code\n'
           '1 hint found.');
     });
   });
 }
 
 MockAnalysisErrorInfo mockError(ErrorType type, ErrorSeverity severity) {
   // ErrorInfo
   var info = new MockAnalysisErrorInfo();
   var error = new MockAnalysisError();
   var lineInfo = new MockLineInfo();
@@ skipping 10 matching lines @@
   when(code.name).thenReturn('mock_code');
   when(error.errorCode).thenReturn(code);
   when(error.message).thenReturn('MSG');
   var source = new MockSource();
   when(source.fullName).thenReturn('/foo/bar/baz.dart');
   when(error.source).thenReturn(source);
   when(info.errors).thenReturn([error]);
 
   return info;
 }